Condenser and method of operating the same



F. A. J. FITZGERALD ET AL 1,810,557

CONDENSER AND METHOD OF OPERATING THE.SAME

June 16, 1931.

Filed March 25, 1929 3 Sheets-Sheet J INVENTORS FRANus A-J.F\T7 GERALD JAMES Kau nae ATTORNEY June 16, 1 931. 7 F. A. J. FITZGERALD ET AL 1,810,557

CONDENSER AND METHOD 0E QPERATING THE SAME Filed March 25. 1929 3 Sheets-Sheet 2 FRANus A .J. FlTlGEIZALQ JAMES KELLER ea ATTORNEY June 16,1931.

F. A. J. FITZGERALD ET AL 1,

CONDENSER AND METHOD OF OPERATING THE SAME Filed March 25, 1929 3 Sheets-Sheet 5 l5 INVENTORS FRANus A. J.F\ T'1GE2ALD AMES KeLLeuse Y A ATTORNEY Patented June 16, 1931 UNITED STATES FRANCIS A. J. FITZGERALD, OF NIAGARA FALLS, NEW YORK, AND JAMES KELLEHER,

PATENT OFFICE A OF CHIPIAWA, ONTARIO, CANADA, ASSIGNORS TO AMERICAN CYANAMID COM-' PANY, OF NEW YORK, N. Y., A CORPORATION OF MAINE CONDENSER AND METHOD OF OPERATING THE SAME Application filed March 25, 1929. Serial No. 349,678.

This invention relates to a method and means for condensing zinc either in the form of liquid metal or a mixture of liquid zinc and blue powder, and either from spelter, impure metallic zinc or from the smelting of zinc ores or other zinc-bearing materials.

One of the important objects of the invention is to provide a condenser assembly in which a plurality of condenser flues are used, each of which is cooled by one or a plurality of independently controlled cooling flues, through which a gaseous or liquid cooling medium may be clrculated. As a result of such a construction, each condenser flue is subject to independent control although operated in a bank of such flues. This close temerature control results in greater efliciency th as to capacity of the condenser assembly and purity of product.

Another important object is the provision of a bank of such zinc condenser assemblies adapted to receive the vapor to be condensed, whether zinc vapor alone or a mixture of zinc vapor and carbon monoxide, from an electric furnace or a zinc retort or a plurality of retorts, or other metallurgical apparatus for the production of zinc vapor, inasmuch as by the utilization of the principles herein disclosed a maximum capacity is assured, due partly to the fact that this condenser design operates on one thin dimension which gives the minimum average difiusion distance to the condensing walls, and causes a swirling action or turbulence in the vapors to be condensed which produces rapid and efiici'ent condensation.

Sill another object is to provide a condenser which will be subject to the minimum amount of wear and tear such as cracking or leaking in use, and to this end it has been found that one with vertical walls is admirably adapted to accomplish this. Such a design permits of the use of less expensive and more durable materials of construction. Where heretofore such condenser walls have usually been made of graphite, with this constructlon they may be made of clay shapes. The latter material not only is a much more durable construction, but as the walls of the condenser are vertical the condensed metal flows down the same and there is no tendency to leak through the joints.

Other objects and advantages will be pointed out as the descri tion proceeds.

To this end the lnvention contemplates a single or bank of condenser assemblies connected to a single or a plurality of retorts, as the case may be, furnishing either zinc vapor alone or a mixture of zinc vapor andcarbon monoxide, through a manifold. The retorts may be of any desired design with which this invention is not here concerned.

The individual condenser assemblies proper consist of a vertical condenser flue of suitable material such as refractory clay shapes, preferably glazed on the inner walls thereof to facilitate condensation and permit the liquid zinc condensed to flow readily down the same to the sum at the bottom thereof. As now arranged it is preferred to admit the zinc vapor at the top thereof, the same passing downwardly under retort pressure. The condensation product is removed at the bottom thereof either intermittently or continuously and the carbon monoxide burned at ports above the normal level'of the condensation product.

As shown, each condenser flue is provided with one or more cooling flues contiguous thereto and having a common thin dividing wall. These cooling flues extend substantially the entire height of each condenser flue and are provided at the bottom with intake ports through which coolingl'air may be admitted and rise to the top t ereof under the influence of convection currents. Several such ports are rovided at various heights so that a difl'erentlal cooling effect may be had at difierent parts of the condenser flue. The various intake ports for coolingfluid may be controlled by' suitable valves. Each cooling flue is provided with individual dampers at the top thereof so that close temperature control may be had of each independent of the other or others. By suitably prpiportioning the dividing walls between con enser and cooling flues, a maximum condensation efl'ect ma be secured.

s shown, the condenser flue has a larger cross-sectional area at the top thereof than at the bottom. This construction causes the I incoming zinc vapors to swirl as they pass downwardly into the more restricted portion of the condenser and this turbulence causes, as a consequence, rapid cooling and condensation of the vapors.

The invention further contemplates the novel construction, combination and arrangement of parts constituting the condenser assembly as herein shown and described, and the method of operating the same.

In the drawings:

Fig. 1 is a sectional elevation of a condenser assembly embodying this invention.

Fig. 2 is a fragmentary sectional plan view along the line 22 of F 1g. 1.

Fig. 3 is a sectional elevation along the line 33 of Fig. 1.

Fig. 4 is a sectional elevation along the line 4-4 of Fig. 1.

Fig. 5 is a front view of the device of Fig. 1.

Referring now with particularity to the drawings accompanying this specification there is shown diagrammatically at 1 a furnaoe or retort of any desired construction furnishing the zinc vapors to be condensed, through a throat 2 which connects with a manifold 3 running along the top of the rear of a bank of condenser assemblies.

The manifold and other portions of the condenser about to be described may conveniently be constructed of refractory clay shapes although obviously the invention is not thereby limited to a construction in which this material is used.

It is to be understood that where a plurality of retorts is connected to such a condenser assembly there will be several throats leading to a common manifold so as to distribute the vaporized zinc to the condensers.

It may be desirable after the assembly has been shut down either for repairs or for any other reason, to initially heat the manifold or other parts of the condenser above a zinc condensation temperature so that premature condensation will not take place.

The condenser assemblies proper consist of a metallic frame work comprising uprights 4 and cross ties 5 of any desired construction adapted to support and give strength to the refractory material of which the various units may be built.

Within the frame work is located a central condensing flue 6 connected to the manifold 3 which flue is composed of thin refractory side walls 7 having glazed opposing faces to facilitate the flow of condensation products down the same. These refractory tiles 7 fonm a dividing wall between the condensin flue 6 and cooling flues 8 on each side thereof. Both the condensing flues 6 and the cooling flues 8 extend vertically from the bottom of the assembly to the top thereof.

Bracing tiles 9 set into the refractory material 10 of the assembly body are provided,

burned. These pilot flames serve the and with the spacing tiles 11 serve to make more rigid the comparatively frail thin dividing walls 7 between the condenser and cooling flues. Neither of the tiles 9 or 11 extends the entire height of the flues but are of the tiles 7 and force them against the members 9.

A cap 12 may be placed on the top of each condenser flue to permit access to the. interior thereof As is clearly shown in Fig. 1, both the condenser and cooling flues have a greater crosssectional area at the top thereof than at the bottom, as the assembly is restricted towards its bottom, and the condenser flue 6 is provid-,

ed with a sump 13 in which the solid or li uid condensation products may be collected. It is contemplated that the various condensing flues of a bank of these assemblies will connect with a common sump. In the case of liquid zinc a tap hole 14 in the end wall may be provided for continuous removal of this liquid condensation product. If blue powder is being collected it will be necessary to remove this material mechanically, as is well known in the art. In like manner skimming holes may be provided at any desired location for the removal of dross.

Above the normal level of the condensation products in the sump, and in proximity to the bottom of the condenser flue, there are provided refractory ports 15 through which the carbon monoxide may escape and be pose of indicating to the operator the condition obtaining within that particular condenser flue. If no flame is issuing therefrom it indicates that that flue is not functioning properly and he may then take the necessary 1 steps to restore it to normal operation.

The cooling flues-on each side of the condenser flue are admirably adapted to receive a cooling fluid such as air. Air may, there-. fore, be admitted at the very bottom of each cooling flue as at 16. Additional ports 17, 18 and 19 are provided to furnish additional air, and all of these ports are controlled b suitable closing valves. In this way a di ferential cooling effect may be secured in any particular portion of the cooling flue by admitting more or less cooling fluid thereto.

It is contemplated that each cooling flue g may be provided at the top thereof with a damper 20 operated as by a control chain 21 so that the passage of cooling fluid through the flue may be absolutely controlled. The cooling air after having served its purpose and having passed the various dampers 20,

will find its way to the stack 22.

pur-

Obviously, pyrometers may be introduced at various polnts in the condenser structure in order to determine the temperature of the various portions thereof, as the eflicient condensation of the zinc depends upon keeping different parts of the condenser at definite temperatures by means of the air circulation. This is important, as by maintaining the vanous points at their proper temperatures,

a small but positive pressure may be maintained in the condenser, thus preventing on the one hand, the formation of a negative pressure which would cause the drawing in of air with the formation of zinc oxide, or on the other hand, the formation of a marked positive pressure, which would result in a loss of zinc through the refractory ports 15. The maintenance of a proper temperature at all points in the condenser is also important, because if at any point the temperature drops below the freezing point of zinc there will be a deposit of blue powder at that point.

It will be apparent that the ports 15 may serve three purposes,.first as indicators of the pressure conditions in the condenser, second to permit the escape of carbon monoxide gas, and third to indicate how the zinc is condensing. The construction of these ports will necessarily vary accordingly as the apparatus is used to condense zinc obtained from the smelting of ore or to condense zinc from spel ter. In condensing zinc smelted from zinc oxide there is a relatively large amount of carbon nlonoxideproduced and hence, the

ports 15 must be of a size suflicient to take care of this volume of gas. On the other hand, when distilling zinc from spelter, there is substantially nothing but zinc flowing into the condenser so that theoretically no ports are needed when the furnace is running normally and all the zinc is condensed. Practically, however, a small hole is necessary,

through which a little zinc vapor escapes and burns. This flame is very valuable as an indication of the working conditions of the condenser.

The flame of burning zinc from this hole should be as small as possible but should burn continuously. If the flame increases in size it is an indication that the proper internal pressure is becoming too great. If, on the other hand, the flame goes out or recedes inside the port, it is an indication that the pressure is too low. These conditions may be then corrected by proper adjustment and manipulation of the parts 16, 17 18 and 19, on the damper 20. In manipulating these parts, however, the temperatures as indicated by the various pyrometers should be taken into account, and they will determine the amount of manipulation and adjustment required.

What is claimed is:

1. A method of condensing zinc vapors condenser, conductim to the top of a vertical condenser'flue, forcingv the vapor to move downward through the a cooling medium upwards on two sides of the condenser through two independent cooling flues, maintaining the temperature of the condenser below the zinc condensation temperature, and collect ing the zinc thus condensed.

2. A method of condensing zinc vapors which consists in conducting vaporized zinc in a horizontal direction into a condenser flue, causing said vapors to contact with a vertical wall and thereby change the direction of flow and move downwardly in said flue, restricting the cross-sectional area of the vapors as they move downwardly, to cause turbulence, maintaining the condenser below a zinc condensation temperature and collecting the zinc thus condensed.

3. A method of condensing zinc vapors which consists in conducting vaporized zinc in a horizontal direction into a condenser flue, causing said Vapors to contact with a vertical wall and thereby change the direction of flow to move downwardly in said flue, restricting the cross-sectional area of the vapors as they move downwardly, to cause turbulence, maintaining the condenser below a zinc condensation temperature, and continuously removing the zinc thus'condensed.

4. A zinc condenser assembly compris ng two vertical flues having a common dlviding Wall, a sump at the bottom of one flue, an aperture below the sump at the bottom of the other flue and an aperture at the top of each flue, whereby vaporized zinc may be conducted down one flue and condensed zinc collected in the sump, and a cooling medium conducted up the other flue for regulating the tempera v ture of the zinc flue.

5.. A zinc condenser assembly comprising a plurality of vertical zinc flues and a plurality of independent cooling flues each of an extent equal to that of the zinc flue, in proximity to each zinc flue.

6. A zinc condenser assembly comprising a plurality of vertical zinc flues, a plurality of independent cooling flues in prox1m1ty to each zinc flue, each cooling flue extendmg from the bottom to the top thereof, and means for independently controlling the flow of coolingmedium through each cooling flue.

' 7. A zinc condenser assembl comprlslng a plurality of vertical zinc con ensing flues, a manifold connecting all of the condenser flues with asource of vaporized zinc, a cooling flue in proximity to each condenser flue, and a damper on each cooling flue to control the flow of cooling fluid therethrough.

8. A zinc condenser assembly comprising a vertical zinc flue, the surface of the inner wall of which is glazed, and a cooling flue in proximity to the zinc flue.

9. A zinc condenser assembly comprising a vertical zinc condensing flue, an independ ent cooling flue on each of two sides of the condenser flue, each cooling flue having a common dividing wall with the condenser flue.

10. A zinc condenser assembly comprising a vertical zinc condensing flue, a vertical cooling flue in proximity to the condenser flue, the cooling flue having a plurality of intake ports therein through which a cooling fluid may be introduced, said fluid being restricted to said cooling flue. V

11. A zinc condenser assembly comprising a vertical zinc condensing flue, a cooling flue in proximity tothe condensing flue, both condensing and cooling flues being of greater cross-sectional area at the top than at the bottom thereof, the portion of greater crosssectional area constituting an overhang, and an airport in the overhang of the cooling flue.

12. A zinc condenser assembly comprising a vertical zinc condensing flue, a cooling flue in proximity to the condensing flue, both condensing and cooling flues being of greater cross-sectional area at the top than at the bottom thereof, the portion of greater crosssectional area constituting an overhang, an airport in the overhang of the cooling flue, and an additional air port at the bottom of the cooling flue.

13. A condenser assembly comprising a vertical zinc condensing flue, a cooling flue in proximity thereto and of equal extent, a sump at the bottom of the condenser flue and a pilot flame port in the condenser flue and above the sump whereby vapor flow and pressure within the condenser flue may be indicated.

14. A zinc condenserassembly comprising a vertical condensing. flue, and a cooling flue in proximity thereto and of like extent, and air ports in the cooling flue at the bottom and sides thereof, each air port being controlled by an independently operated closure.

15. In combination a plurality of retorts supplying vaporized zinc, a manifold receiving vaporized zinc from all of the retorts, a plurality of zinc condensin flues connected to the manifold, a plurafity of independently controlled cooling flues in proximity to each condenser flue, all of the condenser flues connecting to a common sump.

In testimony whereof, We have hereunto subscribed our names this 19 day of March,

FRANCIS A. J. FITZGERALD. JAMES KELLEHER. 

